Originally posted by: ashley20

Hi, 

We have enterprise license for Cplex. We implemented an optimization model by using Python + DoCplex. The DoCplex is installed locally. If 2 or 3 people in our group run the same Python program (with DoCplex) from command lines at same time, will it probably mess up any calculation between each other? If it is, what kind of set up shall we do? 

Thank you!

The solve for each user will run in a different process, thus there is no chance that one process can corrupt the data of another.

However, the different solves of course share the same resources like CPU and memory. It is up the operating system's scheduler when and for how long to run each process. So when running multiple solves at the same time, each solve will be slower and it is basically not predictable how much slower. Also, if your solves are memory-intensive then you may observe that one solve runs out of memory because other solves are using all the memory.

In many cases it is faster to run one solve at a time rather than running multiple solves at the same time. Or to partition the available CPUs between the users (which still requires sharing of memory between them).

Originally posted by: ashley20

Hi Daniel,

Thank you for your answer. Does your answer "The solve for each user will run in a different process" only apply to DoCplex or does it apply to Python+DoCplex?

From Python perspective, do we need to do copy-paste to make multiple Python projects for multiple users? For example, user 1 run Python project copy 1, user 2 run Python project copy 2...

Or can multiple users call the same main file to run the same Python project at same time?

We are new to Python and DoCplex. Thank you!

The fact that solves started by different users run in different processes is not limited to docplex. It applies to all of CPLEX. Actually, it applies to a lot more: in almost any operating system a process that was started by one user (except a super user) cannot corrupt the in-memory data of another user's process unless that process explicitly allows to do so.

Multiple users can share the same script file (as long as they all have read permission on it). Every user running the main file will start a new process, so again, these runs will not corrupt each other (as long as nobody starts editing the file while someone else is running/starting it).

Originally posted by: ashley20

Hi Daniel,

Thank you very much for answering our question.